"There is one male character and one female character available," reads the contest page at Prizeo. "You can choose your character's station in the world (lordling, knight, peasant, whore, lady, maester, septon, anything) and you will certainly meet a grisly death!"

He has already raised more than $260,000 since the contest launched Thursday.

(Watch Martin explain the contest below, where he also pitches taking a helicopter trip with him.)

Other prizes up for grabs including having breakfast with Martin ($15,000), tickets to the Game of Thrones season-five premiere ($7,500) and even Martin's trademark hat ($7,500). There are also lower-ticket items, such as a thank you e-card from Martin ($25) and a T-shirt ($50).

Martin and his wife, Parris McBride, are avowed wolf lovers and say the money will go toward improving the habitats at the Wild Spirit Wolf Sanctuary. It will also benefit a local food pantry, The Food Depot of Santa Fe.

Martin is currently working on the sixth installment of his A Song of Ice and Fire Series. Meanwhile, HBO'sGame of Thrones concludes its fourth season on June 14.